Computational Method of Aging Index for Catalytic Converter Based on Wavelet Transform

Abstract

In order to control vehicle exhaust emission effectively, the conversion efficiency of catalytic converter is one of the key monitoring and evaluated indexes. The signal monitoring system of oxygen sensor is built by the TI2812 microcontroller. The method is to obtain the eigenvector and correlation coefficient of signal energy distribution, and to determine the two signal correlativity by using the Daubechies wavelet functions to analyze voltage signals of front and back oxygen sensors. The noise and vibration source are identified with the correlation coefficient. The aging level of catalytic converter is estimated according to the value of correlation coefficient. Experiments show that the method is more simple and effective than the traditional one.

Keywords

• Automobile
• Catalytic converter
• Wavelet transform
• Correlation coefficient.